Author: HanyiLuo, Yuqi Huo

CVE-2025-29632

the information for the vulnerability covered by CVE-2025-29632

Affected versions: 4.0.0 and previous versions

When free5gc processes the InitialUEMessage, it only checks whether the nASPDU reference is nil (i.e., whether it is a null pointer), but does not verify if the content of nASPDU is empty. This results in passing an empty byte array as a parameter when calling nas_security.DecodePlainNasNoIntegrityCheck(nASPDU.Value) during subsequent message parsing. In this function, accessing the NAS message security header fails due to the empty value, leading to an error and crash in the AMF.

poc.py an exploit script

ngap.pcap is the traffic packet after the script is executed, containing the data sent by the script and the server's response

free5gc.log is the log content of free5gc before and after the attack. The vulnerability was triggered at 00:48:15.913618097+08:00 on March 07T, 2025, causing the AMF to crash